Bach U.S. Pat. No. 4,572,753 discloses a welding tip 10, which may be affixed to an anvil 20 to cooperate with an ultrasonic horn 50, or to the horn to cooperate with the anvil, and which includes a plurality of conical projections 12 alternately interspersed with a plurality of semi-spherical reservoirs 14, or parallel feeder trough portions 26 connected to troughs 22 and 24. The adjacent sheet of material 40 is softened upon being contacted by the conical projections, and displaced to become accumulated in the reservoirs to avoid overheating.
Obeda U.S. Pat. No. 3,499,808 discloses a horn 14 having spherical cylindrical depressions 22 formed therein, for engaging material 17 projected through an aperture 19 of a second material 18, to thereby soften the projection material into a head which is peened over into a rivet-like form.
Slater U.s. Pat. No. 3,886,012 discloses a horn 62 having circular openings or depressions 68 formed in the face thereof for directly opposing aligned openings or depressions 42 formed in a sheet 16, with an intermediate thin, flexible sheet 52.
Each of Bachner U.S. Pat. No. 3,971,300, Fukusima et al U.S. Pat. No. 4,767,492, and Walke U.S. Pat. No. 4,011,800 discloses a horn and a mandrel having oppositely disposed, variably shaped, cooperating projections and depressions adapted to seal various overlapped thicknesses of panels therebetween.
Referred to as prior art in Fukusima et al U.S. Pat. No. 4,767,492, FIGS. 13A, B and C disclose a horn 1 in which a plurality of parallel grooves and ridges 42 extend in a longitudinal direction across the full width of the horn contact surface 3.
European Patent No. 0 185 325 discloses a sealing tool having recessed rhombus-shaped surfaces 6 formed in a flat surface 5, and, alternately, raised rhombus-shaped surfaces 6 formed on the flat surface 5.